1. Field of the Invention
This invention relates to closures for containers, more specifically to a tamper indicating, child proof, reusable snap-off cap and container closure system.
2. Description of the Prior Art
The container closure art is replete with tamper-indicating, child proof designs including caps with frangible elements connecting the cap to the container, and with spring loaded bayonet locking means, spring loaded ratchet means, and other arrangements which make it difficult for a child to open the container once the frangible element is breached.
U.S. Pat. No. 4,449,638, patented May 22, 1984 by E. Davis describes a tamper indicating, child proof design of a container having a cylindrical neck with open top mouth. The mouth opening also continues through a portion of the neck in a vertical finger width slot.
A cap with a rotatable plug and a lower skirt is pressed over the neck, whereby the skirt engages annular raised ridges on the neck of the cap preventing subsequent removal of the skirt from the neck. The plug extends into and seals the open top mouth.
An annular tear band joins the upper portion of the cap with the skirt, and also is attached by telltale bridge members to the plug. Tearing away the band separates the top of the cap from the skirt, and breaks the bridge members to further indicate the initial breach of the closure.
The plug has a radially oriented finger hole which must be accessed by way of the finger width slot, in order to be able to apply upward pressure to the plug by a finger to remove it with the cap top from the container. The upward finger pressure can only be applied to the plug from within the plug.
The top of the plug includes an arrow to help the user rotate the plug finger hole into alignment with the slot.
U.S. Pat. No. 4,449,639, patented by E. Davis, on May 22, 1984, describes a tamper-indicating, child-resistant closure with a cap having a top part, a tear band in the middle, and a captive band at the bottom, cooperating with the neck of the container.
In assembly, the cap is forced onto the neck until a pair of annular parallel raised ridges in the inside of the captive band pass a corresponding pair of annular parallel raised ridges on the outside of the container neck, thereby irreversibly retaining the captive band on the neck.
The top part of the cap has an arcuate internal lug to engage below an arcuate external projection on the rim of the container neck to keep the cap on the container after the tear band is removed by pulling on a pull tab. The cap then cannot be removed until it is rotated so that the lug disengages from the projection to free the cap for removal from the neck. Indication is given for rotation of the cap to the disengagement position, for example, by an upward pointing arrow on the outer surface of the container, and a serrated grip tab by which the cap is lifted, shaped into a downward pointing arrow.
To breach the closure and to open the container, the user tears away the band. Frangible bridge members attached variously to the cap top, tear band, pull tab, and captive band, provide indication of tampering by breaking when the tear band is removed.
The user then lines up the two arrows to bring the cap into position for removal, and urges the cap up and off the container by way of a serrated grip tab.